Falkland Is SG51 2/6 Deep Blue on a Commercial Cover VERY RARE

1901 large part linen-lined registered cover (reduced at left) from Government House (embossed Royal Arms on flap) to Hull UK franked by 1898 2/6 deep blue tied by part strike of Type F4 Falkland Islands cds with (Crown)/Registered mark below and red oval London transit (22 AU 01) alongside with London and Hull arrival backstamps (both 22 AU). Endorsed in pencil under stamp Under 5 1/2 oz which would have required 11d postage + 2d registration but this is undoubtedly a commercial usage and the excess may be explained by insurance fees. Slight faults (stamp with minor creasing) still an attractive and Very Rare usage. SG 41